No abstract

Summary Since emergence of the Nipah virus (NiV) in 1998 from Malaysia, the NiV virus has reappeared on different occasions causing severe infections in human population associated with high rate of mortality. NiV has been placed along with Hendra virus in genus Henipavirus of family Paramyxoviridae. Fruit bats (Genus Pteropus) are known to be natural host and reservoir of NiV. During the outbreaks from Malaysia and Singapore, the roles of pigs as intermediate host were confirmed. The infection transmitted from bats to pigs and subsequently from pigs to humans. Severe encephalitis was reported in NiV infection often associated with neurological disorders. First NiV outbreak in India occurred in Siliguri district of West Bengal in 2001, where direct transmission of the NiV virus from bats‐to‐human and human‐to‐human was reported in contrast to the role of pigs in the Malaysian NiV outbreak. Regular NiV outbreaks have been reported from Bangladesh since 2001 to 2015. The latest outbreak of NiV has been recorded in May, 2018 from Kerala, India which resulted in the death of 17 individuals. Due to lack of vaccines and effective antivirals, Nipah encephalitis poses a great threat to public health. Routine surveillance studies in the infected areas can be useful in detecting early signs of infection and help in containment of these outbreaks.

Zika virus (ZIKV) is a mosquito-borne virus that was first isolated from Zika forest, Uganda, in 1947. Since its inception, major and minor outbreaks have been documented from several parts of world. Aedes spp. mosquitoes are the primary vectors of ZIKV, but the virus can also be transmitted through sexual practices, materno-fetal transmission, and blood transfusion. The clinical presentations of symptomatic ZIKV infections are similar to dengue and chikungunya, including fever, headache, arthralgia, retro-orbital pain, conjunctivitis, and rash. ZIKV often causes mild illness in the majority of cases, but in some instances, it is linked with congenital microcephaly and autoimmune disorders like Guillain–Barré syndrome. The recent Indian ZIKV outbreak suggests that the virus is circulating in the South East Asian region and may cause new outbreaks in future. At present, no specific vaccines or antivirals are available to treat ZIKV, so management and control of ZIKV infections rely mostly on preventive measures.

RT-LAMP assay is rapid, sensitive, specific and cost effective method for detection of influenza A viruses than conventional one-step RT-PCR and it can serve as a good alternate for diagnosis and surveillance studies during influenza outbreaks in resource-limited setups of developing countries.

Chikungunya is a notorious viral infection, which affects a large segment of world populations in absence of vaccines and antivirals. The current study evaluates of anti-chikungunya activities of Psidium guajava leaves extract and their green synthesized silver nanoparticles. Green synthesized nanoparticles were well characterized for their size and stability by dynamic light scattering (DLS), zeta potential, scanning electron microscopy (SEM) and their functional groups were analyzed by FTIR. Maximum non-toxic doses (MNTD) of extracts and nanoparticles were analysed by using Vero cell-lines. Anti-chikungunya activities of extracts and nano-particles were determined on Vero cells and their effects on cell viability were measured by MTT assay. The P. guajava nano-particles and extracts revealed the anti-chikungunya activities in the Vero cell. The cells viability was increased by 40% and 60% as compared to the virus control, when these cells were treated with MNTD of P. guajava nano-particles and extracts, respectively. To know the reason for antiviral activity, molecular docking of phytochemicals was done against a replication essential cysteine protease (nsP2) of Chikungunya. It was found that phytochemicals; Longifollen and Quercetin showed the minimum binding energy with nsP2. P. guajava extracts can be exploited to develop an effective anti-chikungunya agent. In the absence of CHIKV vaccines and antivirals, P. guajava may be used to develop rapid, responsive, specific, and cost-effective anti-chikungunya agents. Supplementary Information The online version contains supplementary material available at 10.1007/s13337-021-00685-4.

Aim: Diagnosis of osteoarticular tuberculosis (OATB) is quite challenging and there is an urgent need to design a prompt and precise diagnostic test. Methods: We developed a multi-targeted loop-mediated isothermal amplification (LAMP) assay using mpt64 (Rv1980c) and pstS1 (Rv0934) targets for the detection of Mycobacterium tuberculosis in OATB patients. Results: The sensitivities of 100 and 82.4% were obtained in confirmed (n = 10) and suspected (n = 57) OATB cases, respectively by multi-targeted LAMP with a specificity of 96.9% (n = 33). Moreover, the sensitivities attained by multi-targeted LAMP in total OATB cases were significantly higher (p < 0.05–0.01) than multiplex-PCR ( mpt64 +  pstS1) and GeneXpert assay. Conclusion: Our LAMP is simple, reliable and cost-effective method, which may develop into an attractive diagnostic kit for early detection of OATB cases.

Herpes simplex viruses (HSVs) cause a latent infection in humans which is mainly associated with characteristic cold sores or fever blisters and genital blisters. Large segments of the world population are suffering from the HSV infection and early diagnosis as well as treatments are needed to avoid further complications. HSV surveillance is very sparse, especially from developing countries including India. The aim of the present study is to develop and evaluate molecular assays for rapid detection and typing of HSV. In the present study, viral DNA was extracted from cerebro-spinal fluid from HSV suspected encephalitis patients. The conventional multiplex PCR for HSV-1 and HSV-2 was optimized and their comparative analysis was done with Real-Time qPCR for detection and typing of HSV. Out of 137 clinical samples, eleven samples (8.03%) were diagnosed as HSV positive by Real-Time qPCR while ten (7.3%) by conventional multiplex PCR which were further typed as subtyping HSV-1 (nine) and HSV-2 (two). Real-Time qPCR is highly sensitive and able to detect 9.4 9 10 1 to 3.1 9 10 6 copies/ml of HSV DNA. Conventional PCR was found to be having 99.21% specificity with 100% sensitivity. The positive predictive value was 90.91% whereas negative predictive value was 100%. Logistic regression indicates blisters with pain and skin rash as the most significant symptoms associated with HSV infection. The present study could be applied for rapid, specific, sensitive and cost-effective diagnosis of HSV-1 and HSV-2 thereby helpful in better patient management through early detection and treatment of HSV.

Transcription factors BABY BOOM (BBM), WUSCHEL (WUS), BSD, LEAFY COTYLEDON (LEC), LEAFY COTYLEDON LIKE (LIL), VIVIPAROUS1 (VP1), CUP SHAPED COTYLEDONS (CUC), BOLITA (BOL), and AGAMOUS LIKE (AGL) play a crucial role in somatic embryogenesis. In this study, we identified eighteen genes of these nine transcription factors families from the banana genome database. All genes were analyzed for their structural features, subcellular, and chromosomal localization. Protein sequence analysis indicated the presence of characteristic conserved domains in these transcription factors. Phylogenetic analysis revealed close evolutionary relationship among most transcription factors of various monocots. The expression patterns of eighteen genes in embryogenic callus containing somatic embryos (precisely isolated by Laser Capture Microdissection), non-embryogenic callus, and cell suspension cultures of banana cultivar Grand Naine were analyzed. The application of 2, 4-dichlorophenoxyacetic acid (2, 4-D) in the callus induction medium enhanced the expression of MaBBM1, MaBBM2, MaWUS2, and MaVP1 in the embryogenic callus. It suggested 2, 4-D acts as an inducer for the expression of these genes. The higher expression of MaBBM2 and MaWUS2 in embryogenic cell suspension (ECS) as compared to non-embryogenic cells suspension (NECS), suggested that these genes may play a crucial role in banana somatic embryogenesis. MaVP1 showed higher expression in both ECS and NECS, whereas MaLEC2 expression was significantly higher in NECS. It suggests that MaLEC2 has a role in the development of non-embryogenic cells. We postulate that MaBBM2 and MaWUS2 can be served as promising molecular markers for the embryogencity in banana.